Hospitals — how this layer is made

What you are looking at

Each dot is a hospital, a place with beds. There are more than 210,000 worldwide. Colour represents whether a hospital has an accident and emergency department, and the size of a dot represents the area of the site. Click on any of them to see what OpenStreetMap records, such as who runs it and its website. If there's a Wikipedia article, we show a short summary and a link to the full article, in your own language where possible.

Where the data comes from

Every hospital here is something a mapper added at the OpenStreetMap website, from a survey, from local knowledge or from aerial imagery. We don't model or estimate anything ourselves, and we haven't merged in any national health register.

What we include

Two tags. `amenity=hospital` is the older and much the larger of the two. `healthcare=hospital` belongs to a newer scheme and adds a few thousand more hospitals that carry it without the first. Both are in daily use, and taking only the older key would lose a set that grows every year.

Clinics and doctors' surgeries are not here. `amenity=clinic` and `amenity=doctors` are far more numerous and describe a different place, one where you are seen and sent home again. Where a hospital is mapped both as a point and as the outline of its grounds, which is common, we merge the two into one feature rather than draw it twice.

Colour

Colour represents whether OpenStreetMap records an accident and emergency department. There are three classes: hospitals recorded as having one, hospitals recorded as having none, and hospitals where nobody has said either way. The third is much the largest of the three.

We would rather have coloured by who runs the hospital, the state or a private owner. OpenStreetMap has a tag for that, `operator:type`, and far too few hospitals carry it, so the map would show where that tag has been used instead.

What a grey dot means

A grey dot is a statement about the record and not about the hospital. It means nobody has written down whether there is a casualty department, and it does not mean there is none. Writing it down is a habit that took hold in North America, western Europe and Australia and has spread little beyond them, so across much of Asia and Africa nearly every hospital is grey. If you hide the grey class, what is left is the part of the world where the answer has been recorded.

Size

The size of a dot represents the area of the hospital site in square metres. About half of hospitals are drawn as an outline, and among those the typical one covers about 7,000 m². We draw the rest at that same nominal size rather than at the smallest, because being mapped as a point tells you about the mapper's time and not about the size of the hospital. Grounds are a fair guide to a hospital's size, since wards, theatres and car parks all grow together. The largest sites are psychiatric institutions built as colonies in open country, the biggest of them several square kilometres, so we cap the size scale well below them.

Where the map is empty

An empty area means nobody has mapped a hospital there, not that a place has none. Hospitals are among the more evenly mapped subjects on this site, because a hospital is a signposted landmark that people nearby know. Mapping is still thinner in parts of central Africa and central Asia. Counting sites also says nothing about beds, staff or the care given in them.

Up to date, mostly

OpenStreetMap is edited continuously, and we take a new copy once every one to three months. A hospital shown here may have closed, and a closed hospital often keeps its buildings for years.

Source and licence

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